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I have a Lennox G51MP furnace. Just built this house last year and the furnace was installed in November, 3 months ago.

Last night, it was 0 degrees out. When my wife woke up me for work, she said "its feezing". When I went down stairs, the thermostat said 51. The furnace obviously shut off in the middle of the night. And, my wife babysits a 3 month old everymorning.

Luckily, I put a set of gas logs in when I built my house, so I quickly got them burning and within an hour the living room was toasty.

I got out my manual from lennox and read the trouble shooting guide.

When the furnace first comes on, both the Red and Green LEDs blink fast, which the manual indicates as normal operation.

It goes through this cycle and then attempts to light... You see the pilot light come on, then a flame, then the flame goes out.

It does this seeral times for about 3-4 minutes then finally shuts down altogether.

The furnace control board has to sense that there is a flame present when it opens the gas valve. If it does not sense this flame it will shut the gas valve so that it is not filling the furnace with raw gas ( so no explosion and fire will occur). From what you describe, your furnace is not sensing the flame. This is not something that you can remedy, it must be done by someone who is knowledgeable about the furnace. If your furnace is 3 months old then it should still be in warranty, call the installer. If it is a small shop, as your previoud post implies, then surely he has some arrangement for a back up to cover his calls. If not, then maybe you picked the wrong contractor. Either way, you will have to find someone to repair the furnace or it will get mighty cold between now and Monday.

Good call Plain Spoken. There are a few items that should be looked over with that code you mentioned. If your service tech you normaly use it out of town you may contact your local gas supplier. They should have a staff available 24 hours a day. Typically if your unit is only 3 months old it will have a warranty active yet.

Honestly. Look in the local phone book and have a service tech address the problem. The tools required to properly diagnose some of the situations that occur on a GAS burning appliance do not always come in a serviceman's canvas bag, but thru adequate training in the profession. Feel free to email me. My email is posted on my credentials link.

FINALLY, someone in this thread makes the CORRECT recommendation. If his normal service provider is not available, STILL ALL A PROFESSIONAL. Suggestions such as turning the power off and back on to possibly reset a safety is okay, but where do we draw the line at making service suggestions to a HO? Very slippery slope here guys! I can certainly sympathize with the HO in a case like this, no heat, newborn, etc. but when are we going to draw the line in trying to service these things over the net? We are so anxious to "display our knowledge" that we overstep the limits of what we can responsibly do in a case like this. It sounds like the installing contractor is a one man show. Surprised if that is the case and he is a Lennox Dealer (I know they like their fair market share.) Did anyone tell this person that the service codes on the board are for the benefit of the service tech to assist him in troubleshooting and repairing the unit? I try to limit HO's to changing filters whenever possible, and as we have learned sometimes that's not even safe to do!

FINALLY, someone in this thread makes the CORRECT recommendation. If his normal service provider is not available, STILL CALL A PROFESSIONAL. Suggestions such as turning the power off and back on to possibly reset a safety is okay, but where do we draw the line at making service suggestions to a HO? Very slippery slope here guys! I can certainly sympathize with the HO in a case like this, no heat, newborn, etc. but when are we going to draw the line in trying to service these things over the net? We are so anxious to "display our knowledge" that we overstep the limits of what we can responsibly do in a case like this. It sounds like the installing contractor is a one man show. Surprised if that is the case and he is a Lennox Dealer (I know they like their fair market share.) Did anyone tell this person that the service codes on the board are for the benefit of the service tech to assist him in troubleshooting and repairing the unit? I try to limit HO's to changing filters whenever possible, and as we have learned sometimes that's not even safe to do!